We know more about the history of the Diocese of Urgell from the 9th century. From the constitution of the Marca Hispanica (Spanish Marchland) in 797, the bishopric - like that of Elna, Girona and Barcelona, which had been restored at the time - joined the metropolitan diocese of Narbonne, which was organised by an order of Charlemagne before 814. At that time it also acquired, in addition to the territories it originally possessed (Urgell, Pallars and Cerdanya with the adjacent lands of Berguedà and the Lillet and Ribes valleys), the "pagus" of Ribagorza to the west. One main event stands out from those times: the consecration of the new cathedral of the Vicus Urgelli around 839 on November 1st, All Saints'Day.

Present at the meeting were Sunifred I (the Count-Marquis of Urgell and the Cerdanya from 834 and of Barcelona and Girora shortly afterwards), his wife Ermessenda and his eldest son Wilfred - who was later known as Wilfred the Hairy - as well as a large number of magnates and a substantial turnout of ordinary people.

An exceptional document and venerable parchment half a metre square, which has been conserved intact in the Chapter Archive. It is not just the consecration of a church; it is the first "Geographical Map of the Pyrenees". The great historian Ferran Soldevila has written this magnificent eulogy: "The Act of Consecration of La Seu d'Urgell is the main document of the free Catalonia of the Pyrenees; it is the most evident sign of a new-born people; we can hear their first hesitant heartbeats, the first murmurs of their voice. This voice speaks with a special accent: if any word is formed for the first time, it already has the cadence and essence of what will be the Catalan language." The Act enummerates 129 villages or places in the Alt Urgell, Andorra and Solsona, 85 in the Cerdanya, 31 in the Berguedà, 42 in the Pallars and 2 in Ribagorza. Many of these names still exist. Parishes and churches, all are minutely described there. The notary who drew up the document knew the country very well. He annotates the names in a certain topographical order.